Childhood sets that stage for self-regulatory and decision making processes that shape health and well-being for a lifetime. Research is rapidly uncovering the fundamental principles and processes which govern how human beings perceive the environment, process information, make decisions, experience, express and regulate emotion, form and change attitudes, beliefs and values, and become and remain motivated to change behavior. Translation of these basic behavioral science findings to applied health problems and scalable interventions that improve health and well-being during the childhood years is a complex challenge. Achieving this goal requires knowledge in three critical domains: trajectories of child development and behavior and their biological underpinnings, parenting as a transactional process with roots in biology, and behavioral intervention implementation. We propose a training program that will supply a cadre of researchers fluent in the integration of these three domains of knowledge. We propose to support 4 post-doctoral fellows per year (2 MD fellows in Developmental and Behavioral Pediatrics and 2 PhD psychologists). Each fellow will participate in a 2-year course of training that will provide them with knowledge and skills in (1) theories of development and behavior; (2) developmental science methodologies (e.g., functional magnetic resonance imaging, functional near infrared spectroscopy, eye-tracking, and observational behavioral methodologies); (3) study design and statistical methodology; (4) translation of behavioral research findings to intervention; (5) presentation skills; (6) critical assessment of the scientific literature; (7) socialization into the profession by seeking consultation and advice; (8) grant preparation and peer review; (9) career planning; and (10) ethical conduct of research. The training program will be based in the Department of Pediatrics in collaboration with the Center for Human Growth and Development (CHGD), an interdisciplinary research unit of the University of Michigan with a 50- year history of robust federal funding. CHGD includes 38 regular faculty members, all of whom hold joint appointments in academic departments, including Developmental and Behavioral Pediatrics, Pediatric Endocrinology, Public Health (Health Behavior and Health Education, Environmental Health Sciences, and Epidemiology), Psychiatry, Social Work, Linguistics, Neurology, Psychology, Neonatology, and Obstetrics and Gynecology. Eighteen faculty with robust funding and mentoring histories are included in the current application. The training will draw on the rich resources at the University of Michigan, including the Robert Wood Johnson Clinical Scholars Program didactic series, the Michigan Institute for Clinical and Health Research, and the Inter-University Consortium for Political and Social Research Summer Program in Quantitative Methods of Social Research. In summary, our training program will prepare leaders in the field of child development. They will be poised to make substantial contributions to improving health and well-being in childhood by integrating biology, behavior, and intervention science.